Lead control for valve-gears



C. T. HARDMAN.

LEAD CONTROL FOR VALVE GEARS.

APPLICATION FILED APR-7.19I9.

1,360,942. Patented Nov. 30, 1920.

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WITNESSE INVE/Vml? charlesl', Jiardnww Qiwr A TTORNEYS C. T. HARDlVlAN.

LEAD CONTROL FOR VALVE GEARS.

APPLICATION FILED APR. 7, 1919.

1,360,942, Patented Nov. 30, 1920.

4 SHEETS-SHEET 2- W/TNESSES IN VEN TOR Isl/mam I $5 CMTLQSTJiZL? A TTOR/VEYS giai/W U.-T. HARDIVIAN. I LEAD CONTROL FOR VALVE GEARS.

APPLICATION FILED 1,360,942. Patented Nov. 30, 1920.

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'Mnm':mu| 1 a mmnlma Ill!HillIIilllillllllllllllflllllflllllillHINll )M WITNESSES INI/ENTOR Charles Tiara/mam A TTOH/VEYS UNITED STATES PATENT. OFFICEVFHV CHARLES TERRELL HARDIYIAN, OF ALBANY, ALABAMA, ASSIGNOR F ONE-HALF TO H. K. ADAMS, OF NASHVILLE, TENNESSEE.

LEAD CONTROL FOR VALVE-GEARS.

Applic ation' filed April 7,1919. Serial No.

To all whom it may concern HARDMAN, a citizen of the United States,

' and a resident of Albany, in the county of Morgan and State-of Alabama, have.in. vented certain new and useful Improvements in Lead Control for Valve-Gears, of

which the following is a specification.

My invention relates to improvements in valve'gearsfor locomotive eng nes, and it consists in the constructions, COHlblIlfitIOIlS claimed.

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A furtherobject {of the invention is to:

provide an automatic lead control IE OIKlOiCO-L motive valve gears, to automatically increase the lead of the steam valve when thereverse;

lever is hooked up for higher speed. j-- H Other objects and advantages will ap pear in the following specificatlon, referings, in which 'g. dis a detail sectional view showing Figure 1 is a diagram of the Walschaert Y: valve gear, showingthe automatic lead control in operative'relationship therew th,

'Fig. 2 is a detailperspective vlew of-the valve stem cross head,

v Fig. 3 isa side elevation of lead control, 3 i 5 the: position of the lead block in the com- 1 Fig. 6 is a detail view'ofthe lift bloclr bination lever, hereinafter referred to, r Fig. 5 is a verticalsec't-ion taken tially on the line 5-5 ofFig. 3,

' ofFig.5',' I

' ig. 7 is a detail perspectiveview 'of thef control shaft, Figs. 8 and 9 are rear and front elevations respectively, of the guide box of the V lift block, and

Fig. 10 is ane dge view of the lift block. As stated above, the improved lead con-f trol generally. indicated G in Fig. 1, is operativelycombined 'with 'the VValsc'haert valve mechanism generally indicated W, so

as to automatically increasethe'leadofthe;

Specification of Letters Patent.

the steam and arrangements herein described andb of operation is fully pointed g had to the, accompanying drawthe improved:

le'ad block 6 above referred to. steamtvalve S. as the speed increases. For

Patented Nov. 30, 1920. 287,974.

- the purpose of describing the invention, an Be it known that I, CHARLES TERRELL.

extended explanation of the construction and mode of operation of the WValschaert valve gear is thought unnecessary.

It has been demonstrated by actual experience, that this particular valve gear has no means for regulating the port opening of valve to properly accord with the various engine speeds. It has been found in actual practice that if enough lead is given" with theordinary lalschaert valve gear to suit high engine speeds, difliculties are subsequently encountered in starting a heavy train, for the reason that the proper lead for high speed will not allow holding. the steam as long as it would be held if' no lead were given at the start. Furthermore,

the pie-admission at slow speed also limits the starting capacity very materially. By

applying the improved'automatic lead control, the above ob ect1ons are all eliminated,

and in order that the invention may be fully understood, attention is directed to the aci out. A guide box 1 which is suitably fixed in 'position on the locomotive, houses a lift block 2, which by reasonof its vertical adjustment is capable of automatically changingthe degree of lead of the steam valve S.

To accomplish this purpose, the lift block El-carries a lift link 3, through the bifurcated end 4 of which a radius bar pin 5 is fitted as'shown in Fig. 5', to centrally sup- .port the lead'block 6. I o The jaws '7 of the radius bar 8, which is v part-of the valve gear, are also pivoted on substanthe'b'arpin 5 and are disposed at the sides of" the block 6, both of said elementsbeing "located inside of the bifurcations 4 on the link 3. In order that the various parts may freely radius bar pin 5' is made; in a plurality of diameters as indicated in dotted lines in" move with respect to each other, the

Fig. 5, so that the respective enlargements of the pin abut adjacent parts, prevent bindingwhen the nut 9 is tightened, and permit the'free relative movement above referred to.

Pivotally mounted on a link 10,'is the combinationlever 11 which has a'slotted head 12 at the upper end for receiving the The cross head pin 13 provides the means of attachcompanying drawings and following descriptlon whereln the construction andmode' ment of the combination lever to the cross 2 head 14 of the stem 15 of the valve S, and

by changing the position of the lead block 6 vertically with respect to the pin 13, the extent of the strokes of the stem 15 is changed and the lead of' the valve S controlled. accordingly.

In other words, the controlling or regulating of the lead of the steam valve Sissimmatter of vertically shifting the P y a the combination lever 11.

fulcrum 5' of 1 When the lead block 6. is adjusted high in .the' slotted-head 12,. longer strokes of the valve stem. will result. Conversely, when p the lead block 6. is low in the slotted head -12,.tl1e strokesof the stem 15 will be corre- V spondingly shorter.

The changing. of the vertical positions of the lead block 6: is accomplished either by the automaticmechanism in Fig. 1 or by Y thefluid pressure operated mechanism. in

Fig.;11..- Either may be used with thesame -result,'or other suitable mechanism may be employed if. such be found more desirable.

L lowering the lead block 6 includes, the control shaft "16,. with a crank 17 on theinner .The means for automatically raising and end forconnection to the lead control rod V a 18, and with a lift crank 19 on the outer end,

a slot block 20 rides in the arcuate slot21 ofthelift block 2, and as thecontrol shaft 16 for connection to the slot. block 20. .The.

- is-turned in its bearings 22, the lift block 2.

and consequently the. lead block 6, raised and lowered, as explained.

Before describing the mechanism in Fig.

11-, whereby; the same result, namely, the

.. raising and lowering of the: lead block 6, is accomplished by means of fluid pressure, the

40. parts of the invention should first be under- 1 stood.

a casting'which is suitably aflixeel-v to some;-

details of construction of the correlated In Figs. 5, 8 and 9, the guidebox generally indicated1, is shown to consist of adjacent. part as for. example, one of the guides 23 on which the'cross: head ll op erates. i

V ward extensions 24 with suitably arranged.

and apertured ears 25 to receive. the cover plate or cap 26which when in place, com-j The upper part theguidebox 1- has for-- v I pletes the channelor guide in which the lift ,ZlJlOOk 2 operates. On removing the guide box cap- 26, the structural arrangement of the rear wall. of th'eguide bOX- can be-seen as, ,shownin- Fig. 9. r V

A recess 27 accommodates the l ft crank r 19.. This crankis. inserted through an openl .ing28' which islarge enough to permit pas-v sage of the crank, before putting the bearing.

cover 29. in place. In Fig. 5, the'recess 27 is shown to extend slightly below the bearing Y portion oftheshaft 16, so as to make room ffor the wheel of thecrank 19. and prevent endwise displacement of the shaft. The arwhich equalsgiof an inchran'gement illustrated keeps the crank 19 in position in the recess,

A boss'80;on the lift block 2, provides a support for: the lift block pin 31 which. is mounted in a similar boss on the lift link 3, as clearly shown in Fig. 5. It is to be observed that the lift link 3 is separated at 32 so as to enable easy disassembling of the adjacent parts atthe radius pin 5, or for other purposes, should there be an occasion necessitating such. a requirement.

As stated. before, the whole invention lies in shifting. the lead block 6 so as to change the fulcrum ofthecombination lever 11 and consequently to increase or decrease the strokes of the steam valve S. In order that those skilled inthe, art may see what the advantages of i theautomatic" lead control are, attention is directed to the following.

VVhenthe Walschaert valve gear is set with no lead the port opening at 25 per .cent'- cutoff is only of-an inch. hen set with inch lead, the port opening at 25per cent-.cut off willbe :1; inch plusof an inch With the improved automatic lead control applied the steam valve is set. with nov lead at full stroke, and inch lead at 25 per cent. cut off.. At, this point of cut on? the port opening willnever be less than of an inch plus ofan inch which equals of an inch. If itbedesired to have more port opening at this pointofcut off, it can beobta'ined by in creasing the lead;

Now, a'sstated: above, there beingno lead atfull travel of the valve, and as the valve travel is shortened, lead occurs and increases ticular speed at which the engine is running. I

ll hile the construction and I arrangement of the improved lead. control. as herein described andclaimed, is'that of a generally preferred form, obviously modifications and changes may be made without departing fromthe spiritof the invention or the scope of the claims.

' 1. An automatic lead control. comprising in combination, a .valve withja: stem, an oscillating actuating'lever pivoted to the stem, anadjacent. guide box, an. adjustable fulcrum for saidlever including a lead block slidably mounted .ina. projecting end of the lever, a supporting link for the block, slidable supporting means for" the link. in said box and revoluble means journaled in said box, including a connection to said slidable means, for changing the position of said fulcrum on operating said revoluble means.

2. In an automatic lead control, means for supporting the fulcrum of a valve actuating lever, including a link; amounting for said link including a lift block with a slot, a relatively fixed guide box including a channel for said block, with an adjacent recess having an opening, and revoluble means journaled on said guide box, with means including a crank having an operative connection to said lift block through said slot, said crank operating in the recess and being insertible thereinto through said opening. I

3. The combination in a lead control, of a channeled guide box with a recess having an opening offset in respect to the recess to provide an intermediate shoulder, a lift block with a curved slot, 'slidable in the channel, and a control shaft with a crank in the recess adjacent to the lift block in pin connection with said slot, sustained in position by engagement with said shoulder.

4. The combination in an automatic lead control, of an oscillating actuating lever with a slotted head, with a valve stem pivoted thereto; an adjustable fulcrum for the lever comprising a lead block in the slot, a guided lift block with a curved slot, and a lift link pivotally carried by the lift block, supporting the lead block; and a shaft with a crank having a pin in the slot to move the lift block by the turnin of the crank shaft. CHARLES TERRI lLL HARDMAN. 

